title: Exogenous Vasopressin-Induced Hyponatremia in Patients With Vasodilatory Shock: Two Case Reports and Literature Review.
abstract: Vasopressin has gained wide support as an adjunct vasopressor in patients with septic shock. This agent exerts its vasoconstriction effects through smooth muscle V1 receptors and also has antidiuretic activity via renal V2 receptors. This interaction with the renal V2 receptors results in the integration of aquaporin 2 channels in the apical membrane of the renal collecting duct leading to free water reabsorption. Thus, water intoxication with subsequent hyponatremia, although rare, is a potentially serious side effect of exogenous vasopressin administration. We present 2 patients who developed hyponatremia within hours of initiation of vasopressin infusion. Extensive diuresis followed its discontinuation with subsequent normalization of serum sodium. One of the patients required the use of hypertonic saline for more rapid normalization of serum sodium due to concerns for potential seizure activity. A review of the literature relevant to the incidence of vasopressin-induced hyponatremia is provided as well as discussion on additional factors relevant to septic shock that should be considered when determining the relative risk of hyponatremia in patients receiving vasopressin.
authors.affiliation: Department of Pharmacy Practice, Lerma Rangel College of Pharmacy, Texas A&M Health Science Center, Kingsville, TX, USA msalazar@pharmacy.tamhsc.edu.
authors.forename: Miguel
authors.initials: M
authors.lastname: Salazar
authors.affiliation: Department of Pharmacy, St. Luke's Hospital, Houston, TX, USA.
authors.forename: Bee Bee
authors.initials: BB
authors.lastname: Hu
authors.affiliation: Department of Medicine, Universidad Anahuac México Norte, State of México, México.
authors.forename: Joyce
authors.initials: J
authors.lastname: Vazquez
authors.affiliation: Kidney Associates, PLLC, Houston, TX, USA Department of Medicine, Division of Nephrology, Baylor College of Medicine, Houston, TX, USA Department of Medicine, Division of Nephrology, University of Texas Medical Branch, Galveston, TX, USA Department of Medicine, Division of Nephrology, The Methodist Hospital Weil-Cornell Medical Center, Houston, TX, USA.
authors.forename: Ruth L
authors.initials: RL
authors.lastname: Wintz
authors.affiliation: Critical Care Services, University General Hospital, Houston, TX, USA Department of Acute and Continuing Care, The University of Texas Health Science Center at Houston, Houston, TX, USA Department of Medicine, University of Texas Medical Branch, Galveston, TX, USA.
authors.forename: Joseph
authors.initials: J
authors.lastname: Varon
mesh_terms: D000305:Adrenal Cortex Hormones / Q000494:pharmacology; D004231:Diuresis / Q000187:drug effects; D005260:Female; D006801:Humans; D007010:Hyponatremia / Q000139:chemically induced*; D008297:Male; D017483:Receptors, Vasopressin / Q000187:drug effects; D012772:Shock, Septic / Q000188:drug therapy*; D012964:Sodium / Q000097:blood; D014662:Vasoconstrictor Agents / Q000009:adverse effects* / Q000494:pharmacology; D014667:Vasopressins / Q000009:adverse effects*; D014869:Water Intoxication / Q000139:chemically induced; D055815:Young Adult
chemical_list: D000305:Adrenal Cortex Hormones; D017483:Receptors, Vasopressin; D014662:Vasoconstrictor Agents; D014667:Vasopressins; D012964:Sodium
keywords: antidiuresis; hyponatremia; vasodilatory shock; vasopressin; vasopressors